1. Field of the Invention
This invention relates generally to wheelchairs for the handicapped, and more particularly to a one-piece molded wheel support wheel formed as a unit for supporting and braking the wheelchair.
2. Description of Related Art
Manually propelled wheelchairs having two smaller castered front wheels and two larger rear wheels are well known. These assistive devices are utilized by users which are physically impaired individuals unable to walk or who find walking difficult and are typically propelled by the user. Such wheelchairs require periodic immobilization and stabilization thereof as determined by the user or attendant and are therefore equipped with a hand-actuated brake assembly (typically one per each braking support wheel) attached to a frame member of the wheelchair frame assembly adjacent the wheelchair seat allowing the user or attendant to selectively move a hand operated lever of the brake assembly to engage or disengage a friction braking member in the form of a bar or plate which presses against the outer periphery of each corresponding tire of the braking support wheels of the wheelchair.
However, due to wheel wear, moisture, dirt, oil and other wheel periphery surface modifying debris or contaminants, the limited pressure exerted by the friction member thereagainst will vary greatly and thus correspondingly affect the degree of braking friction for immobilization of the wheelchair. Should the frictional force between the outer periphery of the rear wheel and the friction member be compromised and reduced, unexpected movement of the wheelchair may be experienced.
A more efficient brake mechanism has been incorporated into battery powered motorized three-wheeled scooters which provide motorized personal transportation for a seated user. These motorized scooters typically include spaced apart coaxially mounted rear wheels, one or both of which serve as a driving wheel connected to the battery powered motor mounted on the scooter carriage and a steerable front wheel which includes a wheel housing supporting a single front wheel and a brake mechanism having a tightenable brake band and drum arrangement. However the steerable front wheel of such power scooters is typically supported between spaced downwardly extending ears or plates of the wheel housing such that the entire wheel and brake mechanism are held on an elongated mounting shaft connected between the lower ears of the wheel housing itself.
The present invention replaces the conventional support wheel and corresponding wheel perimeter brake engaging members with a one-piece molded braking and support wheel which includes a molded-in brake drum wheel operably receiving a brake assembly. Substantially greater consistent braking and immobilization are achieved by providing a brake and support wheel mold formed more efficiently as a unit of wheelchairs and which is substantially less impervious to conditions of tire wear, moisture, dirt, oil and other debris which would typically collect on the outer perimeter surface of the wheel tire.